In recent years, a high definition multimedia interface (HDMI) has been widely used as a digital interface for connecting consumer electronics (CE) devices, and the HDMI has been the de facto standard in the field. In the HDMI standard, signals of a video, audio, and control are transmitted as digital signals by using three data differential line pairs (TMDS Channel 0/1/2). Note that the “HDMI” is the registered trademark.
Now, the maximum value determined in the HDMI standard as a transmission speed of the digital signal is 10.2 Gbps. In consideration of the adoption to a video signal of a 4k2k (QFHD) and a video signal with contents having a higher image quality, the above value of the HDMI is required to be extended to the highest value such as 15 Gbps and 20 Gbps in the current standard in the future.
To speed-up the HDMI, it is considered to increase the number of the data differential line pairs from three for now to four or more. The applicant has proposed a technology for increasing the number of the data differential line pairs to six (Patent Document 1).